Wire or band strapping machine

ABSTRACT

A wire or band strapping machine comprises a driven roll pair for feeding a wire or band toward a guide loop about an object to be strapped, a driven roll pair for reversing the direction of movement of the wire or band to draw the same out of the guide and about the object, and tension means for tightening the wire or band in that reversed direction. The tension means is disposed between the two roll pairs, with the feeding pair disposed closer to the loop than the reversing pair with respect to the direction of travel of the wire or band. The wire or band approaches the loop along a horizontal U-shaped path with the feeding and reversing roll pairs operating on the upper and lower horizontal legs of that path, respectively, and the tensioning means acting downwardly on the wire or band in the bend of its U-shaped path.

[15] 3,667,378 [451 June 6,1972

[54] WIRE OR BAND STRAPPING MACHINE [72] Inventor: Pieter Arnoldus Van de Bilt, Zeist, Netherlands [73] Assignee: N. V. Metaverpa [22] Filed: Dec. 7, 1970 21 App]. No.: 95,687

3,157,109 11/1964 Flamgan et a1. ..l00/26 MacKenzie .1 100/26 3,183,824 5/1965 Cook 3,220,337 1 1/1965 Goland et 211 3,318,230 5/1967 Hilton 100/26 X Primary Examiner-Billy J. Wilhite Attorney-Young & Thompson ABSTRACT A wire or band strapping machine comprises a driven roll pair for feeding a wire or band toward a guide loop about an object to be strapped, a driven roll pair for reversing the direction of movement of the wire or band to draw the same out of the guide and about the object, and tension means for tightening the wire or band in that reversed direction. The tension means is disposed between the two roll pairs, with the feeding pair disposed closer to the loop than the reversing pair with respect to the direction of travel of the wire or band. The wire or band approaches the loop along a horizontal U-shaped path with the feeding and reversing roll pairs operating on the upper and lower horizontal legs of that path, respectively, and the tensioning means acting downwardly on the wire or band in the bend of its U-shaped path.

2 Claims, 2 Drawing Figures PATENTEUJUH 6 I972 SHEET 2 BF 2 INVENTOR BY W *JM ATTORNEYS WIRE R BAND STRAPPING MACHINE The present invention relates to a wire or band strapping machine, in which a wire or band to be provided around an object may be guided about a looped path by means of a feed mechanism having means for holding the free end of the wire or band when said end has reached the end of the looped path, means for reversing the direction of movement of the wire or band so that said wire or band may be pulled out of the guiding path around the object to be strapped, and a tension device. A machine of this kind is disclosed for example in U.S. Pat. No. 3,183,824.

In the apparatus of the above patent, the in-feed and reversal of the band or wire takes place by means of rollers driven in opposite directions, against which the band or wire can be pressed by means of freely rotatable rollers movable from and toward the driven rollers. The pair of rollers by which the wire or band is pulled is located between the band guide frame and the tension device. When using synthetic bands and/or bands in general with little bending resistance, the consequence is that when the band or wire is withdrawn in order to form a loop around the object, said band or wire is not always returned through the slot in the tension device but will bend away in the form of a loop in front of the tension device. The result is that the tension device misfunctions.

The object of the invention is to avoid this disadvantage.

In accordance with the invention, said object is achieved by the fact that the tension device is positioned between the means for feeding the band or wire and the means for withdrawing said band or wire.

By providing the tension device between the feed and withdrawal mechanism and by placing the tension device closer to the guide frame than the withdrawal mechanism, no loop can be formed upstream of the tension device with regard to the direction of feed of the band or wire.

In a preferred embodiment, the tension device is operated by the tension of the band or wire which has been withdrawn.

As a result, the tension in the band or wire at the end of the withdrawal movement is always the same, because the withdrawal means acts until the tension in the wire or band has reached a certain value, whereupon the tension device will impose an additional adjustable tension.

In the preferred embodiment, the operation of the tension device and disengagement of the withdrawal mechanism are effected by means of a switch which can be operated by a roller which can be deflected.

One embodiment of the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a somewhat diagrammatic side elevational view of a band strapping machine according to the invention; and

FIG. 2 shows a fragment of FIG. 1 on a larger scale, showing in greater detail the feed mechanism, the withdrawal mechanism and the tension device.

The wire or band strapping machine shown in FIG. 1 comprises a band guide frame 1 resting on a support 2, a closing mechanism 3 for uniting two ends of a looped and pulled band or wire, such as e.g.. a sealing mechanism, and a feed and withdrawal mechanism, generally indicated at 10. Next to the closing mechanism 3, an end clamp 4 and a cutting-off element 5 are provided. An outlet opening 7, as described in U.S. Pat. No. 3,589,275, issued June 29, 1971, is positioned in a bend 6 of the band guide frame 1. In said bend 6, the band 8 is fed into the band guide frame 1 by means of the feed mechanism. The feed and withdrawal mechanism 10 consists of a feed mechanism, a withdrawal mechanism and a tension device.

FIG. 2 shows the mechanism 10 on a larger scale. In FIG. 2, the band 8 coming from a storage roll (not shown) is fed into the band guide frame 1 via two guide rollers 11 and 12. The roller 11 rotates about a stationary shaft 13 and roller 12 rotates about a shaft 14 secured on a swivelling arm 9. A spring holds the arm in its normal position.

The feed of the band 8 takes place by means of a pair of rollers 15 and 16, the roller 15 rotating about a stationary shaft 17 and being driven by an electromotor 20 in the direction of arrow 30 by means of a belt 18 and a roller 19, said motor being rigidly mounted in the frame 2. The roller 16 rotates about a shaft 21 secured on a sliding piece 22 which can be moved up and down by a pneumatic cylinder 223 secured in the frame 2. In the retracted position of the piston rod of the cylinder 223, the band 8 may pass freely between the rollers 15 and 16. When the sliding piece 22 is moved upward by the cylinder 223, the band 8 is gripped between the pair of rollers 15 and 16 and when the roller 15 is driven by the electromotor 20, the band 8 will thus be fed into the band guide frame I.

The withdrawal mechanism is formed by a pair of rollers 19 and 25, the roller 19 being provided on the motor shaft 26 of motor 20 and the roller 25 being able to rotate about the shaft 27 secured on a sliding piece 28 which is moved up and down by means of a cylinder 196. When the piston rod of the cylinder 196 is in retracted position, the band 8 may pass freely between the rollers 19 and 25, while in the other. position of the piston rod of the cylinder 196 the band 8 is gripped between the rollers 19 and 25. When the roller 19 is driven by the motor 20 in the direction of arrow 31, the band will thus be withdrawn.

A tension device is positioned between the rollers 11 and 12, said device comprising a housing 40 with a slot 41 through which the band 8 passes. The housing 40 is connected to a tube 42 which slides over a guide means 43. A clamping shoe 44 and a lever 46 are located in the housing 40. Lever 46 pivots about a pin 45. The other outer end 47 of the lever 46 is guided in a U-shaped guide means 48 secured to the frame 2. Lever 46 is pivotally connected to the piston rod of cylinder 1 17 at 49, cylinder 1 17 being sected to the frame 2.

When the piston rod of cylinder 1 17 moved downward, first the lever 46 is swivelled downward and will press the clamping shoe 44 against the band 8, as a result of which said band is gripped in the passage 41 of the housing 40. When moving the piston rod of the cylinder 117 further downward, the gripped band will then be carried by the housing 40 and will be tensioned further.

A middle clamp is provided in the block 50 which will close when the band 8 has been tightened around the object to be wound by the rollers 19 and 25 and by the tension device, so that the tension obtained will be maintained until the strapping is completed.

From a consideration of the foregoing disclosure, therefore, it will be evident that the initially recited object of the present invention has been achieved.

Although the present invention has been described and illustrated in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.

What is claimed is:

1. In a wire or band strapping machine comprising means guiding a wire or band about a looped path, means feeding said wire or band to said path, means holding the free end of the wire or band when said end has reached the end of the looped path, means for reversing the direction of movement of the wire or band to withdraw the wire or band to tighten the wire or band about an object to be strapped, and a tension device for tightening said wire or band about said object; the I improvement in which said tension device is positioned between said feeding means and said reversing means and said feeding means is disposed closer to said looped path than is said reversing means with respect to the direction of movement of said wire or band.

2. A machine as claimed in claim 1, said means for feeding the wire or band comprising a driven roller, a freely rotatable roller, and means for urging said freely rotatable roller toward said driven roller; said reversing means comprising a driven roller, a freely rotatable roller, and means for urging said freeleis, further rollers deflecting the wire or band into the shape of a horizontal U whose horizontal legs pass through said driving means and reversing means and whose upright bend passes through said tension device, said tension device acting vertically to impose tension on said wire or band. 

1. In a wire or band strapping machine comprising means guiding a wire or band about a looped path, means feeding said wire or band to said path, means holding the free end of the wire or band when said end has reached the end of the looped path, means for reversing the direction of movement of the wire or band to withdraw the wire or band to tighten the wire or band about an object to be strapped, and a tension device for tightening said wire or band about said object; the improvement in which said tension device is positioned between said feeding means and said reversing means and said feeding means is disposed closer to said looped path than is said reversing means with respect to the direction of movement of said wire or band.
 2. A machine as claimed in claim 1, said means for feeding the wire or band comprising a driven roller, a freely rotatable roller, and means for urging said freely rotatable roller toward said driven roller; said reversing means comprising a driven roller, a freely rotatable roller, and means for urging said freely rotatable roller toward said driven roller, the second mentioned driven roller rotating relative to the band in a direction opposite to the direction of the first-mentioned driven roller, said first driven roller being disposed a distance above said second driven roller, an endless member interconnecting both said driven rollers, a motor for driving one of said driven rollers, further rollers deflecting the wire or band into the shape of a horizontal U whose horizontal legs pass through said driving means and reversing means and whose upright bend passes through said tension device, said tension device acting vertically to impose tension on said wire or band. 